Kisspeptin-10 common uses, half-life, side effects and more

Kisspeptin-10 is the ten amino acid tail of a natural hormone that sits one step above GnRH and switches on the reproductive axis. Researchers use it to probe that axis. People buy it to raise LH and testosterone, for recovery after steroid cycles, and for libido. Every human hormone result for it came from an intravenous drip given in a hospital. Nobody has published giving it under the skin to a man. FDA lists it among bulk substances that raise significant safety risks. No United States pharmacy can compound it.

• Raising LH and testosterone in men
• Recovery of the hormonal axis after anabolic steroid use
• Libido and sexual desire goals
• Probing pituitary and hypothalamic function in research

Vendors advertise daily or several times weekly. Research used single intravenous doses, infusions, or a pump firing every 90 minutes.

Vendors sell 50 to 200 mcg per subcutaneous injection. Published human studies used intravenous doses of 0.01 to 3 mcg per kilogram. The effect peaked at 1 mcg per kilogram and a 3 mcg dose produced a smaller response rather than a larger one. A 100 mcg injection works out to roughly 1.1 nmol per kilogram in a 70 kg man. That looks close to the intravenous doses that work. The comparison assumes skin delivers a dose as completely as a vein does. No study in any species has measured how much of a subcutaneous dose reaches the blood. The only humans given it under the skin received up to 32 nmol per kilogram, about 29 times the marketed amount, and showed no change in gonadotropins.

• Vials are sold labeled kisspeptin 10 mg where the 10 refers to the vial weight rather than the ten amino acid peptide
• Research that used the subcutaneous route delivered small pulses by pump every 90 minutes rather than one daily injection

Plasma half-life measured after intravenous dosing is about 4 minutes, reported as 3.8 minutes in men and 4.1 minutes in women. Levels were undetectable 50 minutes after injection. The longer peptide kisspeptin-54 lasts about seven times as long at roughly 28 minutes. Subcutaneous absorption has never been characterized and that figure cannot be converted into an injection duration.

• Injection-site reactions are plausible but were not characterized in any published study
• Libido, mood, and sex hormone changes are plausible because the peptide acts upstream of LH
• Headache, fatigue, and emotional changes appear in anecdotal gray-market reports
• Supervised intravenous studies lasting hours reported no clear adverse pattern and none tested repeated injection at home

Kisspeptin-10 activates KISS1R, a receptor also called GPR54, on the GnRH neurons of the hypothalamus. The receptor signals through phospholipase C and calcium. Activating it makes those neurons release GnRH. GnRH then drives the pituitary to put out LH and a smaller rise in FSH. LH tells the testes or ovaries to make sex steroids. The response depends heavily on sex and on cycle phase. Men respond to intravenous doses as low as 0.3 nmol per kilogram. Preovulatory women respond and follicular-phase women often do not respond at any dose tested. People born without a working receptor fail to go through puberty. That genetic finding is the strongest evidence that this pathway drives human reproduction.

Kisspeptin-10 has a real human effect reproduced by groups in Edinburgh, Boston, and Islamabad. An intravenous dose reliably raises LH in men. Continuous intravenous infusion for 11 to 22 hours also raised testosterone by roughly a third in two studies of four men each. Every one of those studies measured hormones in blood over hours. None measured fertility, libido, symptoms, or testosterone over weeks. The longest published human exposure is 24 hours. The findings people associate with kisspeptin, meaning egg maturation in fertility treatment and the sexual desire brain imaging trials, all used the longer peptide kisspeptin-54 given intravenously. A subcutaneous pump trial in 13 women completed in 2025 and has posted no results.

• WADA prohibits kisspeptin and its analogs at all times under the section covering testosterone-stimulating peptides in males
• Female athletes should not read that male wording as permission because the unapproved-substance rule catches it either way
• FDA cites immunogenicity risk by some routes and difficulty confirming purity and reports having little safety data for the routes proposed
• No regulator anywhere has approved kisspeptin and no United States pharmacy can legally compound it
• Vials are sold without stating whether they hold the ten amino acid peptide or the longer kisspeptin-54
• Twice-daily dosing of the longer peptide nearly abolished the hormone response within two weeks in women